> You can’t really expect to just toss a binary over the wall and forget about the project for the next decade.

You can on Windows. Microsoft has shown us what a three decades of maintaining an OS to that standard will do to a platform and its software ecosystem. There are definitely pros and cons to taking that approach. These days, as a user I'd much rather have decent emulators of older platforms and operating systems, rather than rely on the current OS to be completely and forever backwards compatible. But that doesn't seem like a good solution for mobile platforms or their app stores.